Santa Clara County prosecutors charged Everett Basham with 10 felonies including three counts of illegally possessing assault weapons, two counts of possessing a destructive device, two counts of possessing bomb-making materials and one count each of making criminal threats, forging and possessing a fake driver’s license.

He also faces misdemeanor charges of carrying a concealed and loaded 9mm handgun in a vehicle.

The 45-year-old Basham did not enter a plea in his first court appearance Friday. His attorney, Jenny Brandt, did not immediately return a telephone message seeking comment.

He is being held without bail until his next court appearance, set for Thursday.

The complaint alleges that Basham sent an unnamed constitutional officer a threatening email on Jan. 11. He was arrested by the Highway Patrol on Tuesday, and Yee said the arrest resulted from an explicit death threat he received after introducing gun control legislation.

Two of the charges allege that Basham possessed assault weapons with detachable magazines. Yee said Thursday that the email threatened him with assassination unless he stopped pushing legislation to ban so-called “bullet buttons,” devices that permit swift reloading of military-style weapons by allowing for the rapid exchange of ammunition magazines.

He also is charged with possessing a shotgun that falls within California’s definition of an assault weapon.